OK now it gets weirder!! not sure what I did but now when I open the project the pins still don't work, but there are no error messages or broken expressions! the bone layers animate but the pin expressions have no errors at all but just stay still.

if i make a new comp, put puppet tool on a layer and add bones this new rig works fine, but the old broken ones are still broken.

For some reason, the bones were unlinked... To fix this, you'd have to link them again using this drodpdown.
I don't know how this happened, maybe if you copied and pasted the layers from one comp to another, stuff like that could break the link.

thanks, ahh that's strange. I can see that could happen if it were copied and pasted, i've had it loose layer info like that before, but I'm pretty sure I didn't do so. Several of my comps broke all at once without be doing anything to them so it must be some bug.